"They nearly killed her. I was furious when they turned round and laughed."

Mrs Lawlor had taken Olivia to the park with their pet dog and was walking along the top path.

"I heard a noise and I thought it was someone using machinery. Suddenly this motorbike hurtled round the corner. They swerved to miss me, but never saw Olivia, who was behind me. They missed her by an inch.

"I was so angry I could have killed them."

Mrs Lawlor said she was appealing to the riders' parents to be responsible.

"They should never have been on a public footpath - and I bet neither was insured.

"Parents are irresponsible fools for allowing youths out into such a public place, where there are small children."

Police are investigating and have appealed for help in finding the youths.